Number Of Controlled Sample:

Test Procedure:

1.     Check the submitted samples whether breaking or cracking

2.     Set the oven to 250 oF (121oC)

3.     Place submitted samples in rack, then in the oven for a minimum of 1 hour or longer to assure that the that the temperature of the ware is the same as the oven setting.

4.     Remove the samples from oven and place directly in 68oF±5 (20oC) water until samples have cooled.

5.     Inspect ware for cracks using magnifier and ink pen and record findings. Dye may be used to assist in identifying cracks and crazes

6.     Increase oven temperature by 25 oF (14 oC)

7.     Only samples that have not crazed or cracked may be returned to the oven

8.     Repeat Step 2) ~ 6) for 275 oF (135 oC); 300 oF (149 oC); 325 oF(163 oC); and 350 oF (177 oC)

Test Requirement:

No crack or craze was found on the samples after performing test.

Test Result:

Sample No.Initial check250oF275oF300oF325oF350oF1      2      3      4      5